The present invention relates generally to mixed-technology microsystems to allow a hybrid integration of photonic, electronic, and micro mechanical elements. It is directed particularly to integrated optical modules to combine various functionalities such as optical channel monitoring, variable optical attenuation, DWDM multiplexing and demultiplexing, optical switching, optical amplification, optical add/drop multiplexing, optical crossconnect switching, or any combinations thereof. Specifically the invention is disclosed as multifunctional intelligent optical modules.
Bandwidth-intensive applications such as Internet access, electronic commerce, multimedia applications, and distributed computing are rapidly increasing the traffic volumes carried by telecommunication networks. Telecommunication systems employing optical fibers as the transmission medium have delivered superior performance and cost advantage for all classes of optical networks including ultra long-haul core, long-haul core, metro core, and edge networks. The emerging optical network technologies like dense wavelength-division multiplexing (DWDM) and all-optical network (AON) can further promote a high-speed and large-bandwidth network access at low cost.
Although traditional telecommunication service providers have increasingly deployed fiber optic cables for both long-haul and short-haul routes, the ever-increasing network traffic has created some constraints on the existing SONET/SDH-based communication network in terms of speed, capacity, connectivity, and management of networks. The traditional telecommunication service providers generally address these speed, capacity, connectivity, and network management constraints either by installing new fiber cables or by expanding the existing fiber""s transmission capacity using high-speed time-division multiplexing (TDM) or DWDM technologies. The formal method is quite expensive and difficult, as it requires a huge investment as well as constant upgrade of the existing fiber network infrastructures. In the latter methods, the DWDM technology increases the number of optical signals, called channels, transmitted simultaneously on a single fiber, whereas the high-speed TDM technology increases a transmission speed of optical signals. The DWDM technology is ideal for a variety of high-capacity networks such as point-to-point or backbone ring networks with minimal switching and routing requirements. AON is a desirable realization of optical networks and some of the essential optical network elements (ONEs) for AON include optical add/drop multiplexer (OADM), optical crossconnect switch (OXC), optical terminal multiplexer (OTM). These ONEs can dramatically improve the efficiency and operation cost of AON compared to the traditional SONET-/SDH-based optical networks by providing xe2x80x9ctransparencyxe2x80x9d to modulation format, protocol and signal bit rates. In the traditional SONET/SDH-based optical networks, the transmission signals within optical networks must be frequently converted between optical and electrical forms. For instance, optical signals should be converted to electrical one at switching ports of SONET/SDH-based network elements and the routing information in the information packet should be analyzed and utilized for a proper signal routing. Then the electrical signal must be converted to optical one for a subsequent signal routing and transmission. These optical-to-electrical and optical-to-electrical signal conversions reduce overall network efficiencies, since it introduces delays and noises. The AON can eliminate these unnecessary signal conversions through the use of transparent ONEs to reduce costs and improve efficiencies. For all of these traditional SONET/SDH-based optical networks and contemporary optical networks of high-speed TDM, multi-channel DWDM, and transparent AON, efficient and intelligent utilization of optical networks is essential for fast network provisioning, reliable protection switching, instant fault detection/correction, guaranteed quality-of-service (QoS), accurate optical performance monitoring, and optimal optical transmission engineering. In particular multifunctional intelligent optical module (IOM) for integrated services and intelligent functionalities are very useful to ONEs in order to manage and to control the optical networks in an efficient and profitable manner.
Accordingly, it is a primary objective of the present invention to provide a multifunctional intelligent optical module (IOM) platform for efficient and intelligent utilization of optical networks.
It is another objective of the present invention to provide unidirectional and bi-directional optical channel monitors with or without spectral filtering based on the multifunctional IOM platform.
It is yet another objective of the present invention to provide diverse and integrated functionalities of dynamic channel controlling, dynamic VOA multiplexing, and smart optical switching based on the multifunctional IOM platform.
Another objective of the present invention is to provide a method of monitoring and controlling Quality-of-Service (QoS) per individual optical wavelength channel with variable priorities by using the multifunctional IOM platform.
It is a further objective of the present invention to provide a method of constructing silicon mirror arrays with a small footprint size to be used for the multifunctional IOM platform.
It is yet a further objective of the present invention to provide a vertical optical switch in order to allow optical signals being routed among vertically positioned cores located at different layers of planar lightwave circuits with multiple waveguide layers.
It is yet another further objective of the present invention to provide monolithically integrated smart OADM module by using two waveguide layers on planar lightwave circuits by integrating DWDM mutiplexer/demultiplexer filters, vertical optical switches, optical channel monitors, and VOAs into a multifunctional IOM platform.
Additional objectives, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. To achieve the foregoing and other objectives, and in accordance with one aspect of the present invention, the multifunctional IOM platform is provided to integrate multiple electronic and photonic devices and components by using planar lightwave circuits (PLC). Still other objective of the present invention will become apparent to those skilled in this art from the following description and drawings wherein there is described and shown a preferred embodiment of this invention in one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.